ML19208D492

Forwards Reactor Basement Concrete Second Testing Program, Prepared by Const Technology Labs of Portland Cement Association

ML19208D492
Person / Time
Site:	Wolf Creek
Issue date:	02/28/1979
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19208D493	List: ML19208D492 ML19208D495
References
NUDOCS 7909280491
Download: ML19208D492 (2)

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l, unsas cas ano wcrmc comur GLCNN L. MOCSTER wett reteastuv.e.a..veens P00RORGlNE February 28 1979 Mr. Karl V. Seyfrit Director, Region IV Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 .

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Re: Docket No. STN 50-482 Subj : Wolf Creek Reactor BLi3 ding Base Mat

Dear Mr. Seyfrit:

The purpose of this letter is to furnish the NRC with an update of current information relating to the ongoing investigation of the Wolf Creek Reactor Building base mat. Transmittal of information at this time is consistent with Kansas Gas and Electric Company / Kansas City Power & Light Company (KG&E/KCPL) policies of keeping the NRC currently informed of developments concerning the Wolf Creek unit.

As indicated in my letter of January 16, 1979 to Mr. Licitra, KG&E/KCPL has initiated a comprehensive testing program at the Portland Cement '

Association's (PCA) Construction Technology Laboratories at Skokie, Illinois, using remnants of the 90-day test cylinders initially produced for the Wolf Creek base mat tests. This program was directed primarily to those cylinders that had reported strengths of less than 5000 psi at age 90 days and those cylinders in which a stress reversal was indicated.

Results from this program are s m rized in PCA Report, " Wolf Creek Generating Station Reactor Basemat Concrete Second Testing Program" dated February 27, 1979, a copy of which is attached for early URC review and co= ment.

The PCA investigations of compressive strengths were based upon tests of 2 x 2 inch et)es cut from previously tested concrete cylinders. Results of these tests according to the PCA report " ... indicate an average corrected strength of 6690 psi, with a range of 5340 to 7960 psi." Petrographic analysis and air content measurements were also made from these remnants and were judged by PCA to be satisfactory. Of particular interest is the PCA conclusion that the test data ". . .strongly suggest that the c: . crete is of high quality, the materials being properly proportioned, batched and mixed." As previously discussed, cylinder remnants can also be c:ade available to the NRC or its representatives for independent testing and g

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P00R~0R8NAL Mr. Karl Seyfrit February 28, 1979 Further field investigations into this matter are presently contemplated involving the batching of concrete using the same mix design and materials ~

utilized during the Wolf Creek base mat pour. These investigations, a part of a total re-examination of concrete production at Wolf Creek site, are being formulated by KG&E/KCPL's technical consultant, Mr. W.R. Waugh, and are intended to establish empirical correlations of these tests with results frca earlier testing and analyses. Of particular interest are tests to establish correlation factors for full size cylinder co=pressive tests as compared to the compressive strength tests perfor=ed by PCA on 2 x 2 inch cubes. On the basis of current schedular data, these field investigations are targeted for co=pletion within the next several months. In view of our plans for conducting full 90-day compressive strength tests, there appears to be little opportunity for i=provement of this preliminary schedule.

As indicated in my letter to Mr. Roger Boyd dated February 21, 1979, we are having PCA perform testing on remnants from 28-day cylinders. This information should be available prior to the results of the field investigation.

We will forward this information to you when it is received from PCA. We will keep you inforaed of the status of these investigations and welcome your representatives to witness any or all tests conducted thereunder.

Although the series of tests of concrete provides a raund technical basis

_ for believing that the compressive strength of the Wolf Creek base mat greatly exceeds the specified 5000 psi, we remain fully committed to resolving questions concerning its acceptability. We will continue to commit all resources at our disposal to achieve this objective.

Yours very truly, ..

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GLK:bb Enc: 1) Portland Cement Assoc. Report cc: Mr. Roger S. Boyd, Director Division of Project Management Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Co= mission Washington, D.C. 20555 Enc: 1) Portland Cement Assoc. Report.

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